After a month of painstaking investigations in the Aarushi double murder case, the CBI appears to be veering around the view that the father of the teenage victim and an accused Dr Rajesh Talwar may be innocent.

Highly-placed sources claimed that till date not a single piece of evidence has been unearthed against Talwar. At the same time, the needle of suspicion was pointing towards the alleged involvement of Rajkumar, a domestic help of a family friend of the Talwars and Talwar's assistant at the clinic -- Krishna. Dr Talwar is currently in judicial custody.

Sources said Talwar getting a clean chit in the case was not ruled out as none of the evidence had pointed to either his or his wife Nupur Talwar's involvement in the sensational case that has attracted nationwide attention.

"We do not go by the media trial. We have conducted our investigations in the most scientific manner and this case was unique in its own way as there were no eye-witnesses," a senior CBI official said, seeking anonymity.

Sources said CBI officials simulated the possible sequence of events on the night of the crime to ascertain whether the Talwar couple could have heard the screams of Aarushi. The statement by Aarushi's parents that they they did not hear her screams appeared to be correct.

The CBI had taken over the investigations in the murder of Aarushi and the domestic help Hemraj on June 1 and are piecing together the evidence that included scientific and circumstantial evidence.

Asked about the Noida Police's action in the case, the CBI sources said some of the Noida Police officials had told the CBI investigators that they were under pressure from

"higher-ups" to solve the case as quickly as possible to end a sustained media criticism of the UP Police.

The Aarushi murder case may have ingredients of lust and alcohol as the CBI sources claimed that arrested Raj Kumar, a domestic help of Durranis, was not at his place after the midnight of the fateful night when Aarushi was killed.

About the claims of his employer, Pradeep Durrani, the CBI sources said that while the employer has been giving the account of his activities till midnight, he is unable to provide Raj Kumar's activities past midnight.

Raj Kumar's T-shirt has been sent to Hyderabad-based Centre for DNA Fingerprinting and Diagnostics (CDFD) for DNA profiling of the blood stains as to whether they were that of Aarushi or domestic help Hemraj, the sources said.

Sources said during the forensic examination blood stains having the grouping similar to Aarushi and Hemraj were found on the apparrel after which the CBI decided to place him under arrest.